Turkey warned Thursday it will declare a border on the continental shelf if the island of Cyprus proceeds with offshore oil and gas drilling activities. The Foreign Ministry's announcement came a day after Cyprus President Dimitris Christofias announced that US firm Noble Energy will soon begin exploratory drilling to confirm deposits beneath the sea bed off Cyprus' southern coast despite Turkey's attempts to prevent such a move. The undersea boundary has been among the most contentious issues in Greek-Turkish relations, with each country trying to mark out where on the continental shelf it can exploit seabed oil and mineral deposits in the Aegean Sea. A move by Turkey to declare such a border would aggravate relations with Greece and Cyprus, which is divided into an EU-member Greek south and a breakaway Turkish north. Turkey does not recognize Cyprus as a sovereign country and strongly objects to the Greek Cypriot search for mineral deposits inside the island's exclusive economic zone. It insists that Cyprus has no right to go ahead with the search before a settlement to reunify the divided island can be reached. Turkish and Turkish Cypriot officials met in Ankara Thursday and agreed to conclude a continental shelf delimitation agreement between them if Cyprus does not stop plans to start drilling activities. Turkish diplomats and energy officials will travel to the island Friday for further talks, the ministry added.